Asphaltic mastics and fibrous mats coated therewith are employed in a number of applications such as, for example, road repair and waterproofing. The adhesive strength of these materials is an important factor in determining fitness and suitability for use. Of particular concern is the effect of water on the asphaltic mastic after exposure for extended periods of time since water exposure necessarily follows from many of the intended uses of the material. Good peel and shear strengths are desired properties since the mastic's ability to maintain a fixed position relative to its immediate environment directly affects the quality and duration of the repair or other application.
Accordingly, it is desired to make and use asphalt compositions that possess good peel and shear strength.
Primers, such as cutback asphalt or a rubber-tackifier resin system in a hydrocarbon solvent, are frequently needed in applying asphaltic mastics and mastic-coated fibrous mats to their intended substrates. The primer is generally coated onto the substrate to prepare it for the asphaltic mastic or the mastic-coated fibrous mat. The need for a primer requires an extra step in, for example, the road repair or waterproofing process. This necessarily requires additional time, labor and materials. It may be difficult to determine how much primer to use and problems may arise from using too little or too much primer. Health and environmental problems can also be created by the evaporation of hydrocarbon solvents used in many primers. It is, therefore, desired to make and use asphalt compositions that do not require pretreatment of the intended substrate surface with a primer.
In brief summary the composition of this invention is comprised of (a) asphalt, (b) at least one alkadiene-vinylarene copolymer, (c) at least one petroleum hydrocarbon resin, and (d) at least one amine-based antistripping agent. The composition may optionally contain an extender oil, mineral fillers or antidegradants. When the above-identified ingredients are mixed together the asphalt compositions of the present invention are produced.
The asphalt compositions of this invention possess the characteristics previously identified as desirable in asphalt compositions in general. The asphalt compositions of this invention will exhibit good peel and shear strengths and an especially impressive retention of those adhesive properties after extended exposure to water. The asphalt compositions of this invention find further advantage in their ability to bind to a substrate without the need of a primer. This primer-free utility of the asphalt compositions of this invention not only represents savings in terms of time, labor and cost by obviating the need for a primer application step but also promotes and advances health and environmental concerns by eliminating the use of primar hydrocarbon solvents.
These asphalt compositions can be used as "mop-on" type waterproofing membranes by applying the composition to surfaces of asphalt, concrete, metal and the like. Examples of specific "mop-on" applications include, but are not limited to, the treatment of building foundations, bridge decks and parking decks. The asphalt compositions are also useful as roof and road repair material that can be applied directly to cracked or weakened areas. A wide range of other applications will be readily apparent to those of ordinary skill in the art.
In the preferred embodiment of this invention the asphalt composition is applied to at least one side of a fibrous mat to produce an asphalt-coated fabric possessing the advantages of the present invention. The utility of these coated fabrics is multifaceted and can be illustrated by a few examples. The coated fabrics can be placed between an existing road in need of repair and a new overlay of asphalt cement to prevent reflection cracking (i.e. the propagation of the underlying cracks through the new overlay of asphalt cement). The coated fabrics can be used to cover seams in new concrete highways before overlaying with asphalt cement. The coated fabrics can be used to waterproof bridge decks, parking decks and building foundations. They are also useful as pond liners and roofing sheets. Numerous other uses and applications will be readily apparent to those of ordinary skill in the art.